All three projects of the Program Project will continuously use recombinant murine and human CD1d molecules for lipid binding studies, crystallography, biochemistry and for the making of tetramers to stain specifically NK1.1 T cells. This production will be best ensured by a Core Facility that can express, purify, biotinylate and distribute the reagent. The Core will also be in charge of quality control by doing for each batch a series of tests that will include: fluorescent binding assay with PE-FITC, control of biotinylation by immuno-depletion on streptavidin-agarose beads, and tetramerization/FACS staining of the NK1.1 + DN32.D3 cell line. The standardization of protocols will guarantee reproducibility between batches. The Core will also monitor storage of recombinant CD1d and usage by the three different groups. No priority will be given to any one them, unless limitations in production impose us to. Finally, the existence of this Core will reduce the cost of production dramatically.